Confocal imaging and in vivo imaging are critical procedures for the successful completion of the PPG. The imaging Core B will provide common imaging resources with quality assurance and economy of scale. Core B will support and manage an Olympus Fluoview Confocal Microscope and an MS in Vivo imaging System. Trained technicians will provide data acquisition and analysis to the various projects in a form that is consistent and reliable and will allow cross comparison of different data sets. The Specific Aims of Core B are: 1. To provide a standardized cell staining service of samples that will be analyzed by either confocal imaging through the PPG imaging Core, or flow cytometry through the Analytical Cytometry Laboratory Shared Service of the Comprehensive Cancer Center. 2. To conduct standardized studies that makes use of Confocal Microscopy imaging for the quantitative analysis of virus protein distribution and subcellular localization, and provide training to the PPG user group. 3. To coordinate access to the IVIS imaging System and provide training to the PPG user group. 4. To develop novel applications of the imaging instrumentation that will enhance the PPG directed research and lead more refined image analysis.